Síntese e caracterização de hidroxiapatita enriquecida com prata e zinco para aplicação em engenharia tecidual óssea

Abstract

The main objective of this work was to study the individual and simultaneous incorporation of Zn2+ and Ag+ ions and their effects on physical-chemical characteristics of the hydroxyapatite (HA) for their application in bone tissue engineering. The chemical analyses confirmed the presence of 0.10% of Zn2+ and 0.13% of Ag+ (relatively to the quantity of Ca2+ ions). The insertion of the metal ions into HA did not cause significant modifications in the crystallinity index compared to pure HA. In the same way, no phase transformation was verified after insertion. No effect was noticed on the lattice parameters after the insertion of Zn2+ comparatively to those calculated to the pure HA. Conversely, the insertion of Ag+ induced a remarkable contraction of the unit cell volume. The thermal treatment strongly increased the crystallite growth for all samples, and also promoted the change from stretched crystals before calcination to spherical ones after calcination. The immersion of the specimens in the simulated body fluid (SBF) allowed the incorporation of carbonate into the HA structure, causing a significant reduction in the crystallite size, accompanied by a stretched and crystallinity index.